Narrative:

We were issued crossing restriction for somto intersection. I believe we were at 15,000' and were told to cross somto at 11,000'. I am new to this aircraft and the captain was flying the first leg of the trip. I'm very familiar with the crossing restriction because it has been published as one of the most violated spots in our route system. The captain, a line instructor, used to 'new guys' like myself, took the time to show me how to start a comfortable descent to make the crossing restriction. 1) he selected vertical speed of 1000' on the mode control panel (MCP), ie, autoplt control. 2) he programmed the crossing restriction into the route page of the RNAV computer. 3) he selected the descent page function of the RNAV computer checking that we were below what the computer considered our most economical descent path to make the crossing restriction. He pointed out that we had a minus value meaning we were below glide path and that we were some 8-10 mi from our computer generated flight idle descent point. 4) he selected the 'capture' command on the descent page to allow the autoplt to switch from the V/south 1000' to the flight idle economical descent upon glide slope intercept. 5) he armed the vertical navigation (VNAV) mode on the MCP. The light armed and it appeared that all was normal. He programmed the computer this way to make a smooth transition from cruise to descent. I remember these points because he was taking the time to show me how the aircraft can be flown to the computer's full capabilities giving the passenger the best possible ride. After the computer was programmed I switched off to get new york's lga and ATIS. I looked up to read 3 DME from yardley VOR and that we were still approximately 500' from level off. About this time center asked us our altitude. Not wanting to incriminate ourselves I said 'leveling at eleven'. The controller persisted and the captain admitted we had missed the restriction and asked if there was a conflict. The controller was not going to provide any further information and switched us to new york approach. By lga we knew that the computer had not done what we had asked it to. We called avionics maintenance out and entered a write-up in the aircraft's maintenance log. The avionics man performed all the self-test functions he knew. All the functions of the computer checked out properly. Our next leg was mine and when we were given a crossing restriction going in to clt on the magic 2 arrival, I programmed the computer as I had just been taught. We both watched as the system gave us the same proper indications as it had done on the previous leg. But this time we watched as the computer took us through our flight idle descent path, maintaining 1000 FPM rate. I pulled the throttles to idle, extended the speed brake and we made our crossing restriction. A second WX log entry was made in clt and the VNAV function was MEL'ed inoperative. Contributing factors: 1) I was distracted from giving the captain a good back-up. I was tuned manually to the yardley VOR but I was too intent on getting the lga information. 2) the ARTCC center controller was not busy and could have questioned our descent path sooner. I realize it is not his responsibility but what about safety from his standpoint? Supplemental information from acn 135292: we were talking about the capture feature, and how it was maintaining 1000 FPM descent rate since it was indicating well below the glide path. Actually, we were above the glide path but the computer malfunctioned telling us we were low. As we cross-checked the VOR (yardley) and DME we realized we were in fact high. We were also involved in getting the ATIS and sending an in-range report to our operations at lga. Since the first officer is new on the airplane, I was more involved in the duties that would normally be done while I was flying.

Related reports:

Google
 

Original NASA ASRS Text

Title: CROSSING RESTRICTION NOT MET.

Narrative: WE WERE ISSUED XING RESTRICTION FOR SOMTO INTXN. I BELIEVE WE WERE AT 15,000' AND WERE TOLD TO CROSS SOMTO AT 11,000'. I AM NEW TO THIS ACFT AND THE CAPT WAS FLYING THE FIRST LEG OF THE TRIP. I'M VERY FAMILIAR WITH THE XING RESTRICTION BECAUSE IT HAS BEEN PUBLISHED AS ONE OF THE MOST VIOLATED SPOTS IN OUR ROUTE SYSTEM. THE CAPT, A LINE INSTRUCTOR, USED TO 'NEW GUYS' LIKE MYSELF, TOOK THE TIME TO SHOW ME HOW TO START A COMFORTABLE DSCNT TO MAKE THE XING RESTRICTION. 1) HE SELECTED VERTICAL SPEED OF 1000' ON THE MODE CONTROL PANEL (MCP), IE, AUTOPLT CONTROL. 2) HE PROGRAMMED THE XING RESTRICTION INTO THE ROUTE PAGE OF THE RNAV COMPUTER. 3) HE SELECTED THE DSCNT PAGE FUNCTION OF THE RNAV COMPUTER CHECKING THAT WE WERE BELOW WHAT THE COMPUTER CONSIDERED OUR MOST ECONOMICAL DSCNT PATH TO MAKE THE XING RESTRICTION. HE POINTED OUT THAT WE HAD A MINUS VALUE MEANING WE WERE BELOW GLIDE PATH AND THAT WE WERE SOME 8-10 MI FROM OUR COMPUTER GENERATED FLT IDLE DSCNT POINT. 4) HE SELECTED THE 'CAPTURE' COMMAND ON THE DSCNT PAGE TO ALLOW THE AUTOPLT TO SWITCH FROM THE V/S 1000' TO THE FLT IDLE ECONOMICAL DSCNT UPON GLIDE SLOPE INTERCEPT. 5) HE ARMED THE VERTICAL NAVIGATION (VNAV) MODE ON THE MCP. THE LIGHT ARMED AND IT APPEARED THAT ALL WAS NORMAL. HE PROGRAMMED THE COMPUTER THIS WAY TO MAKE A SMOOTH TRANSITION FROM CRUISE TO DSCNT. I REMEMBER THESE POINTS BECAUSE HE WAS TAKING THE TIME TO SHOW ME HOW THE ACFT CAN BE FLOWN TO THE COMPUTER'S FULL CAPABILITIES GIVING THE PAX THE BEST POSSIBLE RIDE. AFTER THE COMPUTER WAS PROGRAMMED I SWITCHED OFF TO GET NEW YORK'S LGA AND ATIS. I LOOKED UP TO READ 3 DME FROM YARDLEY VOR AND THAT WE WERE STILL APPROX 500' FROM LEVEL OFF. ABOUT THIS TIME CENTER ASKED US OUR ALT. NOT WANTING TO INCRIMINATE OURSELVES I SAID 'LEVELING AT ELEVEN'. THE CTLR PERSISTED AND THE CAPT ADMITTED WE HAD MISSED THE RESTRICTION AND ASKED IF THERE WAS A CONFLICT. THE CTLR WAS NOT GOING TO PROVIDE ANY FURTHER INFO AND SWITCHED US TO NEW YORK APCH. BY LGA WE KNEW THAT THE COMPUTER HAD NOT DONE WHAT WE HAD ASKED IT TO. WE CALLED AVIONICS MAINT OUT AND ENTERED A WRITE-UP IN THE ACFT'S MAINT LOG. THE AVIONICS MAN PERFORMED ALL THE SELF-TEST FUNCTIONS HE KNEW. ALL THE FUNCTIONS OF THE COMPUTER CHECKED OUT PROPERLY. OUR NEXT LEG WAS MINE AND WHEN WE WERE GIVEN A XING RESTRICTION GOING IN TO CLT ON THE MAGIC 2 ARR, I PROGRAMMED THE COMPUTER AS I HAD JUST BEEN TAUGHT. WE BOTH WATCHED AS THE SYSTEM GAVE US THE SAME PROPER INDICATIONS AS IT HAD DONE ON THE PREVIOUS LEG. BUT THIS TIME WE WATCHED AS THE COMPUTER TOOK US THROUGH OUR FLT IDLE DSCNT PATH, MAINTAINING 1000 FPM RATE. I PULLED THE THROTTLES TO IDLE, EXTENDED THE SPEED BRAKE AND WE MADE OUR XING RESTRICTION. A SECOND WX LOG ENTRY WAS MADE IN CLT AND THE VNAV FUNCTION WAS MEL'ED INOP. CONTRIBUTING FACTORS: 1) I WAS DISTRACTED FROM GIVING THE CAPT A GOOD BACK-UP. I WAS TUNED MANUALLY TO THE YARDLEY VOR BUT I WAS TOO INTENT ON GETTING THE LGA INFO. 2) THE ARTCC CENTER CTLR WAS NOT BUSY AND COULD HAVE QUESTIONED OUR DSCNT PATH SOONER. I REALIZE IT IS NOT HIS RESPONSIBILITY BUT WHAT ABOUT SAFETY FROM HIS STANDPOINT? SUPPLEMENTAL INFORMATION FROM ACN 135292: WE WERE TALKING ABOUT THE CAPTURE FEATURE, AND HOW IT WAS MAINTAINING 1000 FPM DSCNT RATE SINCE IT WAS INDICATING WELL BELOW THE GLIDE PATH. ACTUALLY, WE WERE ABOVE THE GLIDE PATH BUT THE COMPUTER MALFUNCTIONED TELLING US WE WERE LOW. AS WE CROSS-CHECKED THE VOR (YARDLEY) AND DME WE REALIZED WE WERE IN FACT HIGH. WE WERE ALSO INVOLVED IN GETTING THE ATIS AND SENDING AN IN-RANGE REPORT TO OUR OPERATIONS AT LGA. SINCE THE F/O IS NEW ON THE AIRPLANE, I WAS MORE INVOLVED IN THE DUTIES THAT WOULD NORMALLY BE DONE WHILE I WAS FLYING.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.